These devices -- based on the Farnsworth-Hirsch fusor -- have been operating for some time now, and there have been a couple of high school students who walloped the other kids in their science fair classes by producing a working example thereof; the number of individuals who have successfully created fusion in such devices is around 17 (from memory).

There are some significant problems involving these classes of devices (known as inertial confinement fusion devices, or ICF for short), the worst of which is brehmsstrahlung radiation, caused by electrons encountering high-energy ions in the plasma, draining energy from the reaction and thus preventing fusion. Robert Bussard, who has been working on these devices for literally decades now, claims to have a device that solves those problems and is 100,000 times more efficient than any other such ICF fusion machine previously operated.

Previously funded by various ARPA and Navy contracts, his money ran out earlier this year, and so issued an appeal to Google in the form of a talk (link prior is a Google Video recording of the entire hour and a half lecture) in which he requests $200M, of which the first $2-5M would be used to repair his current device, which was damaged in its last run before it failed. With the remaining money, he proposes to build a far larger device that he believes would be ready in six years, which would actually be energy positive and could run a p-11B fuel cycle, which is aneutronic, meaning the only waste product would be helium. (Contrast this with conventional deuterium-deuterium or deuterium-tritium fusion, both of which throw off an energetic neutron, creating all kinds of radioactive side effects and problems in reactor design.)

If he is correct, the world's energy problems would be a thing of the past, we could solve global warming problems, China and India could industrialize without wars over oil supplies (boron is cheap and plentiful in the quantities needed for fusion), fresh water could be manufactured from sea water, dogs and cats would live happily together, etc. If he's wrong, well, he wouldn't be the first guy to make exaggerated claims about fusion success.